A multi-point control unit (MCU) is a device used to perform a multilateral video conference. The MCU serves to simultaneously receive video or audio streams from a plurality of participants and mix the received video or audio streams with one audio/video and provide the mixed audio/video to a conference participant.
In this case, the MCU allocates a port to a participant who intends to participate in a video conference and receives a video signal or an audio signal from a terminal device of the participant connected to the corresponding port. However, since the MCU includes only a limited number of ports, there is a problem that an expensive MCU needs to be additionally installed in order to extend the number of conference participants.
Generally, since one MCU includes 16 to 60 ports, when the number of participants is larger than that of the ports, more MCUs are required to secure the ports corresponding thereto.
Therefore, there is a need for a method for extending participants of a multilateral video conference service, which allows more participants to participate in the conference without additional installation of the MCU.